A polarized luminescence thermometer based on a dye encapsulated metal-organic framework

Temperature is a central concept within the realm of thermodynamics and statistics. Extensive research has been dedicated to luminescence metal-organic framework (MOF) thermometers with adjustable emission. Nevertheless, the majority of the reported ratiometric MOF thermometers rely on multiple luminescent centers that produce dual emission. This reliance on lanthanides raises concerns related to cost implications and potential supply shortages. Polarized luminescence thermometers offer distinct advantages as they are less susceptible to variations in probe concentrations and irradiation conditions. Herein, we successfully establish efficient host-guest systems for polarized luminescence thermometers by encapsulating dyes within the metal-organic framework (MOF) ZJU-28. Due to the alignment of chromophores within MOFs, these systems exhibit polarized luminescence and temperature sensing properties. The synthesized composites, specifically ZJU-28⊃DSM, enable self-referenced temperature sensing in the range from 293 K to 305 K with a sensitivity of 0.025% K, while ZJU-28⊃ACF covers a wide temperature sensing range albeit with a decreased sensitivity. Considering the wealth of porous MOFs and emitting units available, the proposed approach can be extended to other luminescent MOFs by adjusting their pore size and employing different organic dyes, opening up a new perspective for the design of host-guest MOF⊃dye polarized luminescence thermometers.